Agree with Chris
All general consumables and wear and tear items are well avail for Z900 considering the age of the machine.
You will only hit delays if you try to keep everything as factory made NOS parts. Plenty of decent repro functional stuff is out there.
Z Power in UK, Z1 Enterprises in USA and WeBike in Japan have a massive range in stock.
Go out and ride it !! you will be fine
I have some new fuses, stickers & brake parts for them listed on eBay from time to time if you need those -
http://www.ebay.co.uk/sch/markfturner/m ... 7675.l2562